Apparatus for controlling fluid flow



March 4, 1941. R. A. WITTMANN 2,233,659

APPARATUS FOR CONTROLLING FLUID FLOW Filed June 26, 1959 s Sheet-Sheet 1J0 17 F- A 7 1/ L97 I l N I s 1 f; J2 1 4/2 a? if;

J i 4/ 7 J6 A14 March 4-, 1941. wlTTMANN 2,233,659

APPARATUS FOR CONTROLLING FLUID FLOW Filed June 26, 1939 3 Sheets-Sheet2 March 4, 1941. wn 2,233,659

APPARATUS FOR CONTROLLING FLUID FLOW Filed June 26, 1939 3 Sheets-Sheet3 Patented Mar. 4, 1941 PATENT OFFICE APPARATUS FOR CONTROLLING FLUIDFLOW Robert A. Wittmann, Chicago, Ill., assignor to Chicago By-ProductsCorporation, a corporation of Illinois Application June 26, 1939, SerialNo. 281,067

9 Claims.

My invention relates generally to apparatus for controlling fluid flowand it has particular relation to valves operated in response to changein the magnetic character of Curie point metals.

5 This application is a continuation in part of my copendingapplication, Serial No. 228,494, filed September 6, 1938.

Curie pointmetals include those metals and alloys which normally areferromagnetic but 10 which when heated sufllciently become substantiallynonmagnetic. The transition temperature, or Curie point as it is called,at which this change in magnetic characteristics occurs on heating is adistinct property of each particular Curie point 5 metal. For example,the Curie point of nickel is 350 C. and it is at the same temperature onheating or cooling. The addition of 2% chromium lowers the Curie pointtemperature and causes it to take place over an interval of temper- 20ature, 240 C.-280 C., on heating. In contrast the Curie pointtemperature of cobalt is 1100 C. Thus it is seen that Curie point metalswith practically any desired Curie point or transition temperature maybe obtained by employing various 25 metals and alloys.

Valves controlled by changes in magnetic char actor of Curie point metalhave certain inherent desirable features. They have the snap action ofsolenoid operated valves but are not dependent 30 on a current sourcefor continuous operation and. since these valves are simple inconstruction and operation and therefore unusually dependable, they findwide application where these safety features are desired.

35 The object of my invention, generally stated, is to control fluidflow in response to the change in the magnetic character of a body ofCurie point metal by changing the temperature thereof.

An important object of my invention is to control the flow of fluid fuelin a conduit in such manner that when a body of Curie point metal isheated above its Curie point by an incandescent pilot element flowthrough the conduit will be permitted, and when the pilot element iscooled 45 below incandescence the body of Curie point metal will coolbelow its Curie point and the flow through the conduit will be stopped.

Another important object of my invention is to control the flow of fluidfuel in a conduit so that, 50 when a body of Curie point metal is heatedabove its Curie point by a pilot flame fed with the fluid fuel, flowthrough the conduit will be permitted, and when the pilot flame isextinguished the body of Curie point metal will cool below its Curiepoint 55 and flow through the conduit will be stopped.

Another important objectof my invention is to provide control means fora valve which will be opened and remain open when a body ofCurie pointmetal is heated above its Curie point, and which will be closed andremain closed when the 5 same body of Curie point metal is below itsCurie point, which comprises an incandescent heater selectivelycontrolled for initially heating the body of Curie point metal above itsCurie point, and a pilot burner which becomes ignited by theincandescent heater when the valve is opened, the pilot burnermaintaining the body of Curie point metal above its Curie point when theincandescent heater is turned oif, and the valve closing when a thepilot burner goes out.

Another important object of my invention is to selectively control fluidfuel flow to a burner by opening or closing an electric circuit, theflow being prevented if the pilot burner for the main burner becomesextinguished.

Still another object of my invention is to provide Curie point metaloperated valves of improved design.

Other objects of my invention will, in part, be obvious and in partappear hereinafter.

Accordingly, my invention is disclosed in the embodiments thereof shownin the accompanyingdrawings, and it comprises the features ofconstruction, the combination of parts, and arrangement of elementswhich will be exemplified in the construction hereinafter set forth andthe scope of the application of which will be indicated in the appendedclaims.

For a more complete understanding of the nature and scope of myinvention, reference may be had to the following detailed description,taken in conjunction with the accompanying. drawings, in which:

Figure 1 is a longitudinal vertical section of a valve illustrating oneembodiment of my invention;

Figure 2 shows the valve of Figure 1 applied for operation as an elementof a gas range in; stallation;

Figure 3 is a longitudinal vertical sectional view of a modification ofthe valve of Figure 1;

Figure 4 is a vertical sectional view of a valve illustrating anotherembodiment of my invention;

Figure 51s a view taken on line 5--5 of Figure 4;

Figure 6 is a view similar to Figure 2, showing the valve of Figures 4and 5 similarly applied for operation on a gas range installation;

Figure 7 is a longitudinal vertical sectional view of anothermodification of the valve of Figure l;

and 55 Figure 8 is a longitudinal vertical sectional view of amodification of the valve of Figure '7.

Referring now to Figure l of the drawings, a heat operated safety valveis shown generally at 40 which will stop the gas supply to a gas burnerin case the pilot therefor goes out. The valve 40 may be located in agas line 4|, for controlling the gas flow therein, with its inlet 42 andoutlet 43 connected in the line 4| as shown. The valve 40 comprises avalve body 44, preferably made of nonferromagnetic material, with abaffle 45 separating the inlet 42 from the outlet 43. In the baflle 45is a port 46 having its underside ground to form a valve seat. A chamber41 is provided on the top of the valve body 44 and above the port 45 forholding a magnet 48 therein. The chamber 41 may be closed by a cap 49 ofCurie point metal screwed thereon. A conducting strip 58 extends fromthe cap 49 over a pilot burner 5| which is located on the top of theinlet 42.

The pilot burner 5| is fed through a small hole 52 drilled in the inlet42 as shown. A shaft 53 depends from the magnet 48 and a valve member 54is carried on its lower end as shown. When the ends of the poles of themagnet 48 are as nearly touching the cap 49, i. e. a few thousandths ofan inch therefrom, the valve member 54 will be seated in the valve seatof the port 46 closing the same. The magnet 48, when not attracted tothe cap 49, rests on a shoulder 55 which keeps it within operativedistance of the cap 49. A removable plug 56 may be provided in thebottom of the valve body 44 as shown.

In order to more fully understand the operation of the valve 40reference may be had to Figure 2 of the drawings showing generally at 68a gas range installation employing the valve 49. The valve 40 is locatedin the gas supply line 4| which leads to a gas manifold 5|. The manifold6| supplies one, two, or any number of gas burners 62 and 63 which arelighted by the gas pilot 5| through the carry-over or lighting tubes 64and 65. In order to individually control the burners 62 and 63, themanifold 6| may be provided with valves 68 and 61.

When the pilot 5| is lighted, sufllcient heat will be conducted by thestrip 58 to the cap 49 so that it will be heated above its Curie pointand will therefore become nonmagnetic. Accordingly, the magnet 48 willnot be attracted to the cap 49 and it will drop to its place of rest onthe shoulder 55, thus opening the port 46. The port 48 being open, gasthen may be supplied as desired to the burners 62 and 63, which will belighted by the pilot 5|. If however for some reason the pilot 5| shouldbecome extinguished, the cap 49 will then cool below its Curie pointsince it will be no longer heated. When the cap 49 thus cools below itsCurie point and becomes ferromagnetic, the magnet 48 will be attractedthereto and the port 46 will be closed by the valve member 54, ashereinbeiore described. Since the gas supply to the burners 82 and 63 iscontrolled by the valve 40, it is seen that it will be impossible forgas to be supplied to these burners at any time when the pilot 5|becomes extinguished.

With a view to providing a heat operated valve which will shut on thegas supply to a gas burner in case the pilot therefor goes out and whichcan also be selectively operated, I have provided a valve shown,generally, at III! in Figure 3 of the drawings, which is a modificationof valve 48 shown in Figure 1. The valve IIII may be exactly like valve49 of Figure 1, except that the conducting strip extends on both sidesor the pilot burner 5|.

the cap 49. An electric heating element III is provided to heat thestrip 50 on the end opposite The heater l I I may be connected to a pairof energized conductors II2 through a switch H3. It will be understoodthat the switch II3 may be positioned in any convenient location, suchas a bathroom or kitchen, and may be manually or thermostaticallyoperated. The valve I I0 is so designed that the heat supply from boththe pilot burner 5| and the heating element III is required in order toheat the cap 49 above its Curie point and allow the valve 40 to beopened. For example, the pilot burner 5| may be the pilot for a gas hotwater heater and valve ||I| may control the gas supply thereto, theswitch II3 being remotely located such as in a bathroom. When it isdesired to have hot water, switch III will be closed causing the cap 49to receive heat from the heating element I|I. Ii. at the same time thepilot burner 5| is burning, then the valve IIO will open allowing gas toflow through the hot water heater which will be lighted by the pilot 5|.If the pilot burner 5| is out, it will be impossible to turn on thevalve III] since the heat supply to the cap 49 from the heater III isalone not suflicient. When the switch H3 is opened, the heat supply fromthe heating element I II will be cut out and the valve I I0 will thenclose.

This feature described in connection with Figure 3'01 controlling theoperation of the valve H0 in accordance with the combination of the heatfrom a pilot burner and a separate selectively controlled heat source isthought to be broadly new, and it will be understood that the valve H0is illustrative of only one embodiment of this feature. For example, thevalve member 54 might be connected to a bimetallic snap disc. This discmight be heated by both the pilot burner 5| and the heating element IIIand so designed that it would require the combined heat supply of bothof these sources to cause the disc to snap to the open position andthereby open the valve IIII. When it is not thus heated from bothsources, it would remain or snap to the closed position. This sameprinciple of dual heat supply could also be applied to a bulb andbellows type operated valve, In this case it would require the combinedheating effects of both sources to heat and expand the gas in thebellows sufllciently to open the valve and when the gas was not soheated the bellows would contract sufliciently to close the valve.

Referring now to Figures 4 and 5 of the drawings, a compact automaticheat operated safety pilot valve is shown, generally, at I29 designedfor operation in connection with top burners, broiler ovens, anddomestic gas stoves and gas ranges, which uses a minimum of Curie pointmetal. The valve I20 has a valve casing III which may comprise astamping in having inlet and outlet nipples I23 and I24 respectively,welded or otherwise secured thereon. A second stamping I25 provides theback and sides of the casing I2I while the top may be closed by a memberof Curie point metal I26. It will be understood that the nipples I23 andI24 may be fitted on opposite sides of the casing I2| if desired. Themembers I22, I 25 and I26 may be sealed together at the edges withsolder as shown to provide a gas-tight casing. If desired the membersI22, I25 and I28 may have extending flanges with gaskets providedtherebetween and bolted together. Instead of making the casing I2I up orseveral members it might be a casting. The

aaaaese 3 stampings I22 and I26 are preferably made from,

nonierromagnetic metal such as from a zinc or aluminum base metal. Thetop of the casing I2l might also be closed with a nonferromagneticmember and then have the member I26 of Curie point metal secured on thetop of this member outside the casing I2I or secured to the underside ofthe member within the casing I2I. The member I26 in this case would besecured in any manner such as by. soldering, brazing or clamping .orotherwise secured. An outlet chamber I2'I may be secured in the casingI2I between the plate I22 and the backing member I26. The chamber I2'Iwill have a port I29 provided therein and will register with the openingprovided in the stamping I22 for the outlet nipple I24. A valve memberI29 is provided for closing the port I28 and is carried by a horseshoemagnet I30. The poles I32 of the magnet I30 are spaced a short distancefrom the body of Curie point metal I26 when the magnet I30 rests on thebottom of the member I25. When the member I 26 is below its Curie pointand ferromagnetic, the magnet I30 will be attracted thereto carryingthevalvemember I29 into a position closing the valve port I28. The valveI20 should be so designed that whenthe valve member I29 is in the closedposition the poles I32 will be a few thousandths of an inch from themember I26. When the member I26 is heated above its Curie point andnonmagnetic, the magnet I30 will drop therefrom and rest in the bottomof the casing I2I, thereby opening the valve port I28. The heatconductive strip I33 may be secured to the member I26 of Curie pointmetal as shown.

In order to more fully understand the opera tion of the valve I20 anapplication thereof will be described in connection with Figure 6 of thedrawings. In the Figure 6 a gas range installation is indicatedgenerally at I35 which corresponds to the installation 60 of Figure 2except for having the valve 40 replaced with valve I20. When the pilotI36 is lighted sufficient heat will be conducted by the strip I33 to themember I26 so that it will be heated above its Curie point and willtherefore be nonmagnetic. The magnet I30 will not be attracted to themember I26 but will be resting in the bottom of the casing I2I, thusopening the valve port I28. The valve port I28 being opened, gas will besupplied to the burners 62 and 63, Which will be lighted by the pilotI36 through the carry-over or lighting tubes 64 and 85. If the pilot I36should become extinguished the member I26 will cool below its Curiepoint and become ferromagnetic. The magnet I30 will then be'attractedthereto and the port I28 will be closed by the valve member I29. Sincethe gas supply to the burners 62 and 63 is controlled by the valve I20,it is seen that it will be impossible for gas to be supplied to thesebumers at any time when the pilot I36 is not burning.

It will be apparent that the strip I33 may be extended on both sides ofthe member I26 to provide a valve similar to the valve I I0 shown inFigure 3 of the drawings, that is, a safety pilot valve selectivelycontrolledby an electric circuit. In some instances it may be desirableto substitute an incandescent electric heater for a pilot burner.Referring to Figure 7 of the drawings,

'Curie point metal will become heated aboveits Curie point, allowing themagnet 48 to drop and thereby open the valve port 46. When the switchI43 is opened, the heater I4I will cool below incandescence, therebyallowing the cap 49 tocool below its Curie point, whereupon the magnet48 will be attracted thereto, thus closing the valve I40.

In operation the heater MI is positioned so as to ignite the gassupplied to the main burners controlled by the valve I40. That is, theheater I4I constitutes a pilot element. For instance, the valve I40 mayreplace valve 40 in Figure 2 of the drawings. The switch I43 may be manually operated, or may be controlled by thermostatic means, or any otherdesired arrangement. When the switch I43 is open, or at any time whenthe heater MI is not heated to the predesigned degree of incandescence,the valve I40 will be closed.

A further application of the incandescent pilot element described abovein connection with Figure 7 is illustrated by the safety valve I45 shownin Figure 8 of the drawings. In general construction the valve I45corresponds to valve 40 of Figure 1. However, the pilot 5| of valve 40is replaced by a pilot I46 provided in the outlet side of the valve I45. An incandescent heating element I4! is provided adjacent theconductive strip 50, in position to ignite the pilot I46 when gas isflowing therethrough. The heater I4I may be energized from the energizedconductors I48 through a control switch I49, as shown. When the pilotI46 is out, and the switch I49 is open, no heat will be supplied throughthe conductive strip 50 to the cap 49 of Curie point metal, which willthen be ferromagnetic and attract the magnet 48 thereto and close thevalve I45.

The valve I45 is so designed that when the switch I49 is closed theheater I41 will become heated to incandescence and thereupon suflicientheat will be conducted to the cap 49 to heat it above its Curie point.When the cap 49 is heated above its Curie point the magnet 48 will droptherefrom, thereby opening the valve port 46 and allowing gas to flowthrough the valve I45. When the gas begins to flow through the valveI45, gas will be supplied to the pilot I46, which will become ignited bythe incandescent heater I4'I. At this time the switch I49 may be opened,allowing the heater M1 to cool, while the pilot flame providessuificient heat to maintain the cap 49 above its Curie point. The pilotI 46 is positioned so that the pilot flame will ignite whatever mainburners are controlled by the valve I45. It is seen that the controlswitch I49 need only be closed for the short period required to open thevalve I45 and ignite the pilot I46. The control switch I49 may bemanually operated, or by any of the automatic time delay means as arewell known in the art. For example, it may be controlled by a time delayswitch operated in response to a thermostatic device. If for any reason,the pilot I46 should go out, the cap 49 will cool below its Curie point,whereupon the valve I45 will be closed.

It will be noted that valve I20, of Figures 4 and 5, is essentially thevalve 40 of Figure 1, provided in a preferred design. That is, theoperation of these valves are substantially the same. Likewise, valveIIO, of Figure 3, valve I40, of Figure 7, and

valve N5, of Figure 8, may be provided in this or other design.

As pointed out hereinbefore, the temperature sensitive members of Curiepoint metal may be selected with practically any desired magneticcharacteristics. Thus, if a valve is operating where normally theambient temperature is high, the body of Curie point metal must have acorrespondingly high transition temperature so that it will becomemagnetic when not heated above the ambient temperature. However, this isa matter of design, depending upon the application to be made of theheat controlled valve in each instance.

Although in all of the foregoing embodiments of my invention the valvesare normally closed when the bodies of Curie point metal are not heatedabove their Curie point and ferromagnetic, and are open when they areheated above their Curie point and nonmagnetic, it will be understoodthat by placing the valve closing members above the valve ports, insteadof below them, as shown, the valves will then be normally closed whenthe bodies of Curie point metal are heated above their Curie point andwill be open when the bodies of Curie point metal are not so heatedabove their Curie point. Some applications may require such amodification.

In all of the foregoing embodiments in which permanent magnets are shownor described, it will be understood that they may be replaced byelectromagnets if these are desired for any reason.

Since certain further changes may be made in the foregoing construction,and different embodiments of the invention may be made without departingfrom the scope thereof, it is intended that all matter shown in theaccompanying drawings or described hereinbefore shall be interpreted asillustrative, and not in a limiting sense.

I claim as my invention:

1. Means for controlling fluid fuel flow in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions, means for establishing a pilot flame,electrical heater means,

and relatively movable cooperating magnetic members, one being apermanent magnet and the other being a body of Curie point metal, saidvalve member being operatively connected to and movable with one of saidmagnetic members, said pilot flame and electrical heating means beingarranged and adapted to Jointly heat said body of Curie point metalabove its Curie point so long as both said pilot flame is establishedand said electrical heating means is in operation, whereby said valvemember remains in the open position.

2. Means for controlling fluid fuel flow in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions, means for establishing a pilot flame,electrical heater means, relatively movable cooperating magneticmembers, one being a permanent magnet and the other being a body ofCurie point metal, said valve member being operatively connected to andmovable with one of said magnetic members, and means for conducting heatfrom said pilot flame, so long as it remains lighted and from saidelectrical heating means so long as it is in operation, to said body ofCurie point metal for maintaining the same above its Curie point,whereby said valve member remains in the open position until either saidpilot flame is extinguished or until said electrical heating means isdeenergized.

3. Means for controlling fluid fuel flow in a conduit comprisin incombination, valve means in the conduit including a valve member movablebetween open and closed positions, means for establishing a pilot flame,electrical heater means, magnet means operatively connected to andmovable with said valve member, and a body of Curie point metalstationarily mounted in the fleld of said magnet means, said pilot flameand electrical heating means being arranged and adapted to jointly heatsaid body of Curie point metal above its Curie point so long as bothsaid pilot flame is established and said electrical heating means is inoperation, whereby said valve member remains in the open position.

4. Means for controlling fluid fuel flow in a conduit comprising, incombination, valve means in the conduit including a valve member movablebetween open and closed positions, means for establishing a pilot flamefed from the fuel in 3,

said conduit, electrical heater means, magnet means operativelyconnected to and movable with said valve member, and a body of Curiepoint metal stationarily mounted in the field of said magnet means, andmeans for conducting heat from said pilot flame so long as it remainslighted, and from said electrical heating means so long as it is inoperation, to said body of Curie point metal for maintaining the sameabove its Curie point, whereby said valve member remains in the openposition until either said pilot flame is extinguished or until saidelectrical heating means is not in operation.

5. A valve comprising, in combination, a fluidtight casing with a fluidinlet and outlet, a valve 1" port, a valve member for closing said port,a magnet operatively connected with said valve mem ber, a body of Curiepoint metal disposed adjacent to the poles of said magnet, and a heatcor.- ductive strip secured to said body of Curie point metal, saidmagnet being attracted to said body of Curie point metal when below itsCurie point and thereby holding said valve member in a position to closesaid port, and said body of Curie point metal being adapted to be heatedabove its Curie point by heat conduction through said heat conductivestrip to thereby become nonmagnetic allowing said magnet to move awayand carrying the valve member so as to open said port.

6. A valve comprising, in combination, a fluidtlght casing having afluid inlet and outlet, a valve port serving to interconnect said inletand outlet through said casing, a valve member for closing said port, ahorseshoe magnet supporting said valve member, a body of Curie pointmetal I secured to said casing adjacent to the poles of said horseshoemagnet and a heat conductive strip secured to said body of Curie pointmetal, said horseshoe magnet being attracted to said body of Curie pointmetal when below its Curie point to thereby hold said valve member in aposition closing said port, and said body of Curie point metal beingadapted to be heated above its Curie point by heat conduction throughsaid heat conductive strip, thereby becoming nonmagnetic and allowingsaid horseshoe magnet to drop and carry said valve member away from saidport, and said horseshoe magnet being free to move away from said bodyof Curie point metal when not attracted thereto.

7. A safety valve for a main burner comprising, in combination, afluid-tight casing with a fluid inlet and outlet, a valve port, a valvemember for closing said port, a magnet movably mounted within saidcasing and operatively connected with said valve member, a body 0! Curiepoint metal disposed adjacent to the poles of said magnet, and a pilotburner for heating said body or Curie point metal above its Curie point,said magnet being attracted to said body of Curie point metal when belowits Curie point and thereby holding said valve member in a position toclose said port, and said magnet moving away from said body of Curiepoint when above its Curie point so as to open said port.

8. A self-contained heat responsive valve comprising a closed casinghaving an inlet connection and an outlet connection separated by a wallwithin the casing, said separating wall having a valve port with a valveseat facing downwardly. a valve plug adapted to be raised to seat toshut oi! the flow of fluid through the port, an armature of paramagneticwhen heated, and a permanent 5 magnet disposed within the casing andconnected to said valve, said magnet gravitating downward to open theport when the armature is paramagnetic and being attracted to thearmature to close the port when th armature is diamag- 1o netic.

9. The valve of claim 8 wherein the said wall within the casing is aclosed end tubular wall, and wherein the permanent magnet is a horseshoe magnet with the free limbs thereof lying on each 18 side of saidtubular wall.

ROBERT A. WITTMANN.

